Modeling and Analysis of Semiconductor Supply Chains

SCM Planning for the Semiconductor Packaged Goods, Purpose and Challenges

The purpose of any demand supply network is to meet prioritized demand on time without violating constraints and as much as possible meet business policies (inventory, preferred suppliers, request and commit date, etc.). Typically, the demand supply network for the production of semiconductor based packaged goods (SBPG) is divided into FAB and POST-FAB. The dynamic interaction between the two is limited in nature for logical and historical reasons. One reason is the nature of complexity which makes life interesting for planners is different between FAB and POST-FAB. FAB has long routes, re entrant flow, deployment and the ever present shadow of the operating curve – to name a few – generating wafer start/ cycle time focus. POST-FAB is faced with constant exit demand uncertainty, allocation of shared components and capacity to competing demands, alternative operations; transport decisions, and the all-important “plan repair” – name a few – generating an exit demand / efficiency frontier focus. Their differences become clear when examining the nature of the models (from spreadsheets to optimization) supporting decisions and analysis. The purpose of this presentation was to provide overview of the current best practices for central planning and identify computational challenges to reduce the current slack and make these networks more responsive.

Master Planning and ATP Fusion in Supply Chains

The Planning process to manage the Demand Supply Network (DSN) for the production of semiconductor based packaged goods is focused on understanding and capturing the exit demand, intelligently matching assets (WIP, Inventory and Capacity across the network) to create a projected supply linked to demand and synchronize the activities of the DSN and planners workbench.

Process Models Demand and Inventory Planning, ATP, Master Planning

The event driven process chains Demand Planning - Master Planning - ATP Usage New orders enter via the Order Handling System. A new order entry triggers the provision of confirmed and pending orders to Demand Planning. The output from demand planning is is a demand outlook, which is provided to Master Planning. Master Planning accepts further inputs from Capacity Planning and Production management.

The output is a projected supply (i.e., available supply with a set of conditions such as pricing and given lead times) depending on the business model of the company. The supply picture is provided to ATP usage, which involves an Order Promising System. The ATP usage activity is usually run according to an order fulfillment event. It results an order response that is sent to the customer.